Method for producing detergent blocks



Aug. 29, 1950 R. J. SHORT Erm.

METHOD FOR PRODUCING DE'LERGENT BLOCKS 2 Sheets-Sheet 1 Filed May 1, 1945 MA1-H FTE. c?.

RjBE/T I SHOR T GEORGE M )f1/noon UFF.

INVENTORS Aug. 29, 1950 R. J. SHORT ETAL METHOD FOR PRonUcING DETERGENT BLocxs 2 Sheets-Sheet 2 Filed May 1, 1945 :n F WM O w 5w TM RE .pbG B 0. R Rw G INVENTORS. BY Mayu@ atented ug.

2,520,570 Y METHOD FOR PnODUoING DETERGENT BLOCKS Robert J. Short, Wyoming, and George M. Woodruff, Cincinnati, Ohio, assignors to The Procter & `Gamble Company, Cincinnati, Ohio, a corporation of Ohio Application May 1, 1945', seria1No.591,29o

3 Claims. l Y

This invention relates to a process for the manufacture of formed cakes of plastic material containing distinctive colored inserts.

The principal object of the invention is to provide a process for inlaying distinctive inserts in a plastic condition in detergent bars without forming a cavity for the insert in a separate operation with a separate die.

Another object is to provide a process which is ,controllable and which gives uniform results in the production of trim detergent bars with distinctive inserts.

In accomplishing the above objects in accordance with the present invention, the insert is rst formed by forcing plastic detergent, preferably of distinctive color, into atubular sleeve die or former whose cross sectional outline of the outside surface corresponds to the desired shape of the insert and whose inside surface at least substantially corresponds thereto. The depth to which the plastic insert material is forced into the sleeve die and therefore the length of the insert formed is controlled by a plunger having controlled movement within the sleeve die. Then the sleeve die containing the insert backed by the plunger is employed as a solid plunger die and is forced the desired depth into a blank plastic detergent bar which is held in a suitable bar mold of desired shape, thereby simultaneously forming the cavity for the insert and positioning the insert therein. The sleeve die is then withdrawn from the detergent cake and simultaneously the plunger within the tubular sleeve die is moved toward the cake compressing the insert material and forcing the samev into the cavity as the sleeve die is withdrawn, thereby fixing the insert in theA cake. The invention will now be described more specifically with the aid of the appended drawings in which an apparatus for conducting the process is shown.

Figure 1 shows an elevation front view of an apparatus suitable for use in the practice of our invention, essential parts of the insert mechanism being shown partly in section;

Figure 2 is a sectional view taken on line 2-2 of Figure 1 showing more clearly the cam arrangement for operating the sleeve die and plunger mechanisms;

Figure 3 diagrammatically shows the relative Vsleeve die and plunger positions at various stations on the cam;

`Figure 4 is a sectional View diagrammatically showing the relative positions of insert elements of the apparatus at the end of the stage where 2 the detergent insert has been formed within the sleeve die;

Figure 5 is a sectional view diagramatically showing the detergent bar positioned in the bar die box with plunger and sleeve die containing the insert at Station Aof Figure 3;

Figure 6 is similal` to Figure 5 and shoWs the relative positions of insert elements after the insert has been forced into the detergent bar but before the sleeve die has been withdrawn. This position corresponds to station B of Figure 3;

Figure 7 is similar to Figures 5 and 6 and shows the relative sleeve die and plunger positions at station C of Figure 3;

Figure 8 is similar to Figures 5, 6 and '7 and shows the relative sleeve die and plunger positions at station D, and

Figure 9 is a cross section of a finished soap bar containing the inserted distinctive detergent.

Referring rst to Figures 1 and 2, numeral IIJ in-dicates a soap press base provided with suitable supports i i and having a pair of anchor posts I2 rigidly mounted thereon. The end of each anchor post opposite the base end is turned down so as to provide a shoulder I3 on which is mounted a hydraulic cylinder lli held rigidly against the shoulders I3 in a suitable manner, the use of nuts I5 being shown. The head of the hydraulic cylinder is-tapped as at I6 to provide for a pipe connection leading to a source of hydraulic pressure not shown.

The hydraulic cylinder I is provided with a bore Il along its main axis in'iconnection with the tapped portion I6 to which is attached the source of hydraulic supply. The bore Il is adapted to accommodate piston I8 for vertical movement, a suitable packing gland i9 being provided at the opposite end 0f bore il to permit movement of the piston I8 within the bore under pressure without appreciable loss of hydraulic fluid.

Aguide bearing 2G, which is preferably adjustable as, to vertical position between the hydraulic cylinder I4 and base lil, is mounted rigidly on guide posts I2 and held in position by means of set screws 2| thereby providing a suitable bearing surface 22 for the piston I8 and a means for maintaining the piston in vertical alignment with the bore Il of the hydraulic cylinder I4.

The lower end of the piston I8 is provided with a die plunger 'block 23 on and within which is mounted a mechanism for inserting the distinctive inserts into the detergent bar. This die y. plunger block at its lower end is provided with a cavity 23a, the sides 24 and 25 acting as guides aseorzo vrial within-the sleeve 'dies-'33 and the. remainder ofthis material in the clearance spacebetween the injection die 5I and top Adie 28, thereby providing for lclean rupture when the dieplunger block 23 is raised preparatory to forcing the inserts into Vthe detergent bar. With suitably controlled mechanism the material in .thesleeve dies 33 mayactually be severed from the excess, but Lit is `not necessary that complete severance be effected. Weakening the line of contact without actually establishing a separation of the insert from the excess 'material above the-insert die 5l is suiiicient to permit-a clean break of vthese two bodies of detergent when the. die plunger block-israised. W @l M f y Although-'the detergent contacting surface 32 of the top dieV 28 may be'suitably lubricated-to prevent the insert material from sticking thereto, we find 'it advantageous tol provide the lugs'59 with undercut edges 60 which fill with the insert detergent material and therebyassist `in disengaging the'insert material Afrom theface of the-top die 28. 'For the samereason the outer edges of therinjection die 5l may be undercut as at 6I. 1 A

Aperatures 62 are-also provided inthe sides of the die box 49 communicating with the interior of the cavity 58 partially occupied by the insertion die 5l and so positioned as to provide for an escape of excess insert detergent material lwhen the die -plunger block 23 Yis forced into position overdie 5I containing a "suitable amount of plastic insert detergent material whereby the insert material is caused to flow intothe sleeve die 33. The size of the escape opening is of course suficiently small'so that the vdetergent material will flow therethrough only after the sleeve die is filled.l

It has 'been pointed out above that grooves 41 are provided in base In to accommodate the die slide plate 48, to which is attached the die box 49, and permit registry of either insert die 5I or lower die 52 with the top die 28. To facilitate in the registry of these two dies, indentations 63 are suitably positioned in the groove 41 for the registry of vball bearing 64 backed by spring 65 mounted in pocket 66 vof the slide die plate 48. Other equivalent means ofY locating positionsof registry may also be used. -f

In the operation of vour process, shown stepwise in Figures 4 to V8 inclusive, an amount of distinctive-insert material, normally inthe form of a thin slab of colored soap and somewhat lin excess of the amount necessary to formv inserts of the desired shape and size, is positioned in the cavity above the injection die 5l. At this point the die plunger block 23 is in a raised position and the plate cams 4| and 4-2 are located at station A, as shown in Figure 2. 'They die slide plate 48 and affixed die box 49 are moved sothat the injection die 5I is in registry with the top die 28. Hydraulic fiuid under pressure is then admitted into bore l1 and the top die 28 is forcibly moved down into the cavity above the injection die 5l causing distinctive insert detergent material contained therein to move by plastic flow into the tubular sleeve die 33, the amount being limited and controlled by the position of the plunger 34. The faces of the top die and of the injection die and the cavity of the injection die are so related in shape and dimension as to result in the squeezing of the distinctive detergent material into the openings of the sleeve dies, thus filling them insofar as is permitted by the plungers 34. Suiiicient clearance is preferably pro- .videdrbetween plunger 34 andthe sleeve die 33 to permit the escape of air as the insert material is forced into the tubular sleeve die, but the clearance is notsuflicient to permit passage of plastic detergent. Y The relative .positions of the various elements at the end of this operation are diagrammatically shown in Figure 4. A J

After formation of the insert has beencom-l pleted, hydraulic pressure is. released and the die plunger block 23 'is raised. The die slide plate 48 and die box 49 are thenmoved so that-the bottom die 52 is in registry with the top die 28. A blank bar of detergent is positioned in the bottom die 52 and with plate cams 4l and 42 at station A hydraulic iiuid is introduced intothe bore I1 of the cylinder I4 thereby forcing the' die plunger block 23 into stamping relationship with the blank bar of detergent contained in bottom die 52. The blank bar is thereby given the shape of the mold. This position is shown in Figure 5. Y l

Reference is now made to Figure 6; After the top die 28 with filled tubular sleeve die 33 has been brought into stamping relationship'l with the blank bar and shape of the mold has been given to the bar, and while he top die is held in position under pressure, plate cams 4I and 42 are moved with the aid of hand lever 45 to station B. In so moving the plate cams the plunger y345 and sleeve die 33 with insert material contained therein are simultaneously forced into the molded bar, preferably without change in relative position. The sleeve die 33V and contained insert Inaterial thus act asv an insert cavity former. The increase in volume .in the soap cake brought about by this insertion is taken care of by the yieldable manner in which thetop die 28 is held in position by the hydraulic mechanism including piston I8. This is the preferred arrangement Asince positive pressure is applied at all times during the bra-forming` operation and a well molded bar results.

However, if the top die is operated by purely mechanical means instead of by the hydraulic means shown, then provision for mechanical movement of the top die can be included in the apparatus to compensate for the increase in volume of the Vbar caused by the insertion of the sleeve die 33 and the contained insert material. Other means may be employed to accomplish this end without departing from the spirit of the invention.

The depth to which the insert is forced into the detergent bar is not a limitation of the invention, but we find that when the distinctive insert includes letters of the alphabet, then the insertion is advantageously made only halfway into the bar. Suitable adjustments and design of plate cams may be provided for consistently limiting the depth of this insertion which may be through the bar to the face of the bottom die if desired. The relative positions of the plunger, tubular sleeve die, etc., at the end of this processing step are shown in Figure 6.

After the insert sleeve die 33 with insert has been pressed into the detergent bar the desired depth, the plate cams 4l and 42 are moved through station C to station D, in which operation the sleeve die is withdrawn and simultaneously with this withdrawal the plunger 34 compresses the insert material and forces the same into the cavity left by the sleeve die 33. The insert thus fits tightly in the cavity. Figure 7 .diagrammatically illustrates the relative positions the various' parts Ypressing the Vinsert ".i'n'the face @of .the bar.

Y'7 i when station C has A'been reached'..V j Yi. Figure i8 `Vtdiagr-ainmatically Villustrates :the ative positions of the yelements at stationD. 1t Willbe noted that theredges of the plunger 34 4and ,of the .sleeve .die 33' are adjacent and. preierably slightly below the .face .of the .bar thereby I-llowever, such .insertion of the ,insert maystopat the face ofthe banin'whichcase it may .or may not .be desirable .to-stamp .the bar subsequently depending on theinisl'led appearance that is defsired. Y

Hydraulic pressure is tlrnereuponY released,l the V.die plunger blockV 23 is raised, yand the ,stamped bar containing the insert is eiected by rai-,Sing

plate A.cams has been described stepwise orderr to simplify the description and that in yactual operation movement fromV station A tostation D maybe continuous Without change inthe nal result.

'Ihe detergent yloar containing the distinctive detergent insert may be subjected to va final stamping operation to impart to the Vbar Ia Vpdlished or' finished appearance that 'it' may not otherwise have, and 'to' insure 'locking the insert in' position. 'Such 'added step, however, is .not essential or necessary `in realizing the benefits of onrinvention.

From the above description of the Aprese-mit process and apparatus, it' will be noted that v,the sleeve die for the insert material isloaded and discharged from the same opening, Ythat positive control is exercised i-n the formation of the insert', and Athat the use of -a separate plunger die to form the insert cavity in the 'bar is eliminated. @ther advantages, including ease of adaptation to= vautomatic machine practice, will be' obvious; It Zis- .also-obviouslthat theY process herein de scribed and claimed may be practiced eith'er'iby hand or by the' .use oi automatic ymechanicalV devices constructed a manner ,suchthat the individual elements of the machine carryingiout the `various .operations of the process may ,be

Y suitably-synchronized. Y

Having thus described our invention, what fwe cla-im and desire tolsecure by Letters Patentist..

-1. In the process of :making a detergent bar. containing -a distinctive detergent insert-, the steps of conning a blank, solid, plastic deter@ gent lbar -underyielding pressure, orcing. -into said I.loa/,r ga hollow Yinsert former -ljled- .with al dis-f tinctlve plastic insert detergent material amount not exceeding fthe amount necessary Afor forming said. insert, while-holding saidv olistir redV tive.l plastic detergent vinsert material. in substantially Istationary position-with respect to saiifihiii` termine .seid insert. and while,

.3. the process .of makina a detergent :bar

containing a distinctive detergent insertl the siens 0f, :Stamping blank, lsolid,v .plastic .detergent bar luider yielding pressure whereby .Said bar yisforced .to a bar :mold and attain the shape thereof, :.for. e :finto e .hello-,w .insertsleeye dieV e VV.dist.matite -:n1-aside insert :material fin. en amount anotexceedine the amount tried undereyieldine mressuremthin- Qld, ,forcing into Vsaid confined bar .said hollow :in-f sert sleeve die While holding said distinc plastie :detergent Z.insert material in :erbeten ily stationary position with -r ,n t 0 said fsleeye die whereby it@ kdistinseelastic detergent of the bar and form .a cavity therein. and ithefsaiter withdrawing ,said .insert sleeve die, leaving the saidimsertfmaterial .insei .simule taneously forcing the Y.dist .e elastic lsieierv gent insert material its w171,11 tnt portion @i the cavity left :py withdrawal ofY said hollow ,sl-eene die.

ROBERT J. sneer- 4 :REFERENQESQQTED Y.

,Name V-MQIXWBII 

1. IN THE PROCESS OF MAKING A DETERGENT BAR CONTAINING A DISTINCTIVE DETERGENT INSERT, THE STEPS OF CONFINING A BLANK, SOLID , PLASTIC DETERGENT BAR UNDER YIELDING PRESSURE, FORCING INTO SAID BAR A HOLLOW INSERT FORMER FILLED WITH A DISTINCTIVE PLASTIC INSERT MATERIAL IN AMOUNT NOT EXCEEDING THE AMOUNT NECESSARY FOR FORMING SAID INSERT, WHILE HOLDING SAID DISTINCTIVE PLASTIC DETERGENT INSERT MATERIAL IN SUBSTANTIALLY STATIONARY POSITION WITH RESPECT TO SAID INSERT FORMER DURING SAID FORCING STEP, THEREBY DISPLACING PLASTIC DETERGENT OF THE BAR AND FORMING A CAVITY THEREIN, AND THEREAFTER WITHDRAWING SAID INSERT FORMER WHILE SIMULTANEOUSLY EXPELLING THE SAID INSERT MATERIAL THEREFROM SO THAT SAID INSERT MATERIAL REMAINS IN THE CAVITY OF SAID BAR. 